Cardio pulmonary resuscitation (CPR) has been established since the 1960s as an effective means of helping maintain some circulatory flow in a patient having cardiac arrest. The exact mechanism by which CPR exerts its beneficial effect has been debated over the years, however. It was thought that CPR depended on compression of the heart by externally applied pressure on the chest. Another view holds that CPR is effective through pressure generated upon the pulmonary blood pool as the patient's chest is being manually compressed.
More recently, it has been recognized that a forceful cough brings about violent muscular movements in the chest and diaphragm sufficient for causing an effect similar to that produced by the standard CPR. According to the Merck Manual, coughing is also thought to induce an electrical impulse to the heart, which may help interrupt an otherwise fatal arrhythmia. The cough by the patient leads to generation of an electrical stimulus delivered to the heart, and is also known as a “vagal maneuver” which is voluntary. The cough technique has also been labeled in the literature as “cough CPR” (also CCPR).
In the past twenty years, the medical literature has come to recognize CCPR as a viable method for maintaining some blood circulatory flow in a patient having cardiac arrhythmia or cardiac arrest (also known commonly as a “heart attack”). Cough-CPR, accomplished by abrupt, forceful voluntary coughing by the patient has been shown to maintain consciousness of the patient through its rhythmic compression of the heart and through initiation of a voluntary vagal maneuver to affect the heart's electrical activity. The method of CCPR has several advantages over external CPR when used in the cardiac catheterization laboratory, and may be applicable to other situations where serious rhythm disturbances are experienced before unconsciousness occurs. Cough-induced cardiac compression or electrical impulse intervention is essentially self-performed by the patient, and compared to external chest compression is less likely to traumatize the chest wall or heart. In addition, CCPR can be performed by the patient in any position and on any surface.
Some medical experts have recommended that patients undergoing coronary arteriography be previously trained to cough abruptly and repeatedly every 1-3 seconds. Nevertheless, these same experts are of the opinion that the potential for utilizing this technique in other circumstances (i.e., CCU, home) is less favorable than during catheterization-induced ventricular fibrillation, perhaps because in the cardiac lab setting the physician is at hand and able to assist the patient. CCPR, however, might also be employed successfully in patients with premonitory symptoms of ventricular arrhythmias or Stokes-Adams seizures. In these cases, the prior training of high risk individuals and their spouses to induce effective coughing in the victim might be lifesaving.